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Base‐Promoted Direct Cascade Transformation of Chromones to Coumarins via Benzannulation and Transesterification
Author(s) -
Cai Hongyun,
Khanal Hari Datta,
Lee Yong Rok
Publication year - 2021
Publication title -
asian journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.846
H-Index - 44
eISSN - 2193-5815
pISSN - 2193-5807
DOI - 10.1002/ajoc.202100039
Subject(s) - transesterification , chemistry , intramolecular force , yield (engineering) , base (topology) , cascade reaction , organic chemistry , cascade , coumarin , transformation (genetics) , combinatorial chemistry , catalysis , mathematical analysis , materials science , mathematics , chromatography , metallurgy , biochemistry , gene
A mild base‐promoted reaction between 3‐substituted chromones and β ‐keto esters for the easy access to various coumarins with structural diversity is described. This protocol provides highly functionalized 3‐acyl‐4‐arylcoumarins in good‐to‐excellent yield via benzannulation and transesterification. A reaction mechanism containing Michael addition, 1,5‐H shift and intramolecular transesterification is proposed.